生物传感用巨磁电阻传感器及其磁珠检测性能  

Detection of Commercial Magnetic Microbeads with Giant Magneto Resistance Sensors

作　　者：王永强[1] 冯洁[1] 陈翔[1] 李福泉[1] 石海平[1] 

机构地区：[1]上海交通大学微纳科学技术研究院,微米/纳米加工技术国家级重点实验室,薄膜与微细技术教育部重点实验室,上海200240

出　　处：《真空科学与技术学报》2009年第4期359-363,共5页Chinese Journal of Vacuum Science and Technology

基　　金：国家高技术研究发展计划863项目资助(No.2007AA04Z310)

摘　　要：本文采用直流磁控溅射沉积了结构为NiFeCo(缓冲层)/[Cu/NiFeCo]×10/Ta,巨磁电阻(GMR)值为9.8%的多层膜,利用微细加工技术制备了基于此GMR多层膜的生物传感器,GMR电阻线条的线宽分别为3μm和5μm。测试了单个GMR传感器的特性,并将该传感器件和外接可调电阻组成惠斯通电桥,采用该GMR电桥对Dynal公司的MyOne磁珠进行了检测。分别测试了施加变化垂直磁场和施加间歇式恒定垂直磁场时GMR电桥信号对传感器表面覆盖磁珠的响应,研究了GMR电桥信号和磁珠覆盖率的关系。选用器件电阻线宽分别为3μm和5μm的传感器测试了器件线宽对传感器灵敏度的影响。结果表明,GMR传感器能够检测到磁珠的存在,最低能检测的磁珠数量约100个,且GMR电桥信号与磁珠覆盖率基本成正比,器件的灵敏度与传感器线宽基本成反比。The commercial＂MyOne＂ magnetic micro-beads, provided by Dynal Biotech, were detected with a labbuilt, magneto resistance（GMR） sensor. The sensor was fabricated with NiFeCo（buffer layer）/[ Cu/NiFeCo] ×10/Ta multilayers with a GMR value of 9.8 %, grown by dc magnetron sputtering. The characteristics of a single GMR sensor were tested. Then, a GMR-Bridge, resembling a Wheatstone bridge, was Constructed by connecting two GMR sensors and two external adjustable resistors to detect the beads. The influence of the bead-coverage on the response of the GMR-Bridge in a vertical varying magnetic field, and in a vertical pulsed magnetic field, respectively, was studied. The impact of featm＇e size of the GMR sensor on its detection sensitiviy was also studied. The results show that the lab-built GMR sensor is capable of detecting the beads,about 100 at least,and that the GMR-Bridge signal is proportional to the surface coverage of the micro-beads on GMR sensor,but its sensitivity is inversely proportional to the feature size of the sensor.

关 键 词：生物传感器 GMR电桥 磁珠 生物检测 

分 类 号：TB79[一般工业技术—真空技术] O484[理学—固体物理]